There were 16 more frogs in green pond than in blue pond. all the frogs from blue pond jumped into green pond. now the total number of frogs in green pond is 80. how many frogs were there originally in green pond?

Let the number of frogs in the Blue Pond be x
Blue Pond = x 
There were 26 more frogs in Green Pond than in Blue Pond
Green Pond = x + 26
There were 80 frogs altogether
x + x + 26 = 80
2x + 26 = 80
2x = 80 - 26
2x = 54
x = 27
x + 26 = 27 + 26 = 53

There were 53 frogs in the Green Pond originally.

Were is the problem